Diethylstilbestrol (DES) Update: Recommendations for the Identification and Management of DES-Exposed Individuals

To review the literature on the long-term health effects of exposure to diethylstilbestrol (DES) among women prescribed DES during pregnancy (DES mothers), among their children exposed inutero to the drug (DES sons and daughters) and among the progeny of these exposed sons and daughters (DES grandchildren). English-language articles were identified through MEDLINE and CANCERLIT searches and through review of the bibliographies of identified articles. All human studies relevant to long-term health effects of exposure to DES were reviewed. Descriptive data on existing DES cohorts were extracted from early publications. Risk estimates for health effects were extracted from published reports. An estimated 5 to 10 million Americans received DES during pregnancy or were exposed to the drug in utero. Exposure to DES has been associated with an increased risk for breast cancer in DES mothers (relative risk, < 2.0) and with a lifetime risk of clear-cell cervicovaginal cancer in DES daughters of 1/1000 to 1/10,000. The association between DES exposure and testicular cancer in DES sons remains controversial. Exposure to DES has also been linked to reproductive tract abnormalities in DES sons and daughters that consist of immune system disorders and psychosexual effects. No evidence for transgenerational effects currently exists. Recommendations for screening persons exposed to DES are reviewed. Further research is needed to define long-term health effects related to DES exposure. Such research would provide a basis for counseling persons exposed to DES and would further understanding of environmental and pharmacologic compounds similar to DES.

Transgenerational effects of diethylstilbestrol (DES) have been reported in animals, but effects in human beings are unknown. Alerted by two case reports, we aimed to establish the risk of hypospadias in the sons of women who were exposed to DES in utero. We did a cohort study of all sons of a Dutch cohort of 16284 women with a diagnosis of fertility problems. We used a mailed questionnaire assessing late effects of fertility treatment to identify boys with hypospadias. We compared the prevalence rate of hypospadias between boys with and without maternal DES exposure in utero. 16284 mothers (response rate 67%) reported 8934 sons. The mothers of 205 boys reported DES exposure in utero. Four of these children were reported to have hypospadias. In the remaining 8729 children, only eight cases of hypospadias were reported (prevalence ratio 21.3 [95% CI 6.5-70.1]). All cases of hypospadias were medically confirmed. Maternal age or fertility treatment did not affect the risk of hypospadias. Children conceived after assisted reproductive techniques such as in-vitro fertilisation were not at increased risk of hypospadias compared with children conceived naturally (1.8, 0.6-5.7). Our findings suggest an increased risk of hypospadias in the sons of women exposed to DES in utero. Although the absolute risk of this anomaly is small, this transgenerational effect of DES warrants additional studies.